Millstones



` (No Model.)

2 sheets-sheet 1.

J. f3. OBBNGHAIN.

(No Model.) 2 sheets-sheet 2.

J. T. OBBNCHAIN.

MACHINE POR DRESSING MILLSTONES.

No. 282,760. Patented Aug. 7, 1883.

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JOHN T. OBENCHAIN, or LoeANsronT, INDIANA.

MACHINE FOR DRESSINSGIIVIILLSTONES.

SPECIFICATION forming part of. Letters Patent No. 282,760, dated August7, 1883.. Application filed November 14, 1882.' (No model.)

To @ZZ whom it may concern,.-

Be it known that I, JOHN T. OBENCHAIN, a citizen ofthe United States,residing at Logansport, in the county of Cass and State of Indiana, haveinvented new and useful Iniprovements in Machines for DressingMillstones, of which the following is a specication.

This invention relates to a machine adapted for dressing the furrowswhich have been roughed out in a millstone, and also for dressing offanylumps occurring in the face or lands of the stone.

The object of my invention is to provide means for adjusting andsupporting the rotary.

cuttershaft either in a vertical or in an inclined position, so that thecutter shall rotate in a plane coincident with the surface to bedressed; also, to provide means .for adapting the Vcutter to make adeeper cut toward either end of the furrow, and to give a twist to thebottom of the same; and, further, to adapt the rotary cutter, whilebeing fed along the furrow, to either preserve the same depth of cutthroughout or to deepen the furrow at either end, and also to'eitherwiden the furrow toward either end thereof or to. preserve the samewidth throughout, whereby the furrow can be either widened and deepenedor narrowed and deepened at either end.

A further object is to provide certain novel features of constructionand combination tending to produce an improved machine' for dressingmillstones, all as hereinafter-describedand illustrated in the annexeddrawings, in which- Figure 1 is a perspective view of thev machine; Fig.2, an enlarged elevation of the rear of a portion of the carriage withthe supports and cutter, the bed-plate being shown in this figure incross-section. Fig. 3 is a top or plan view, and Fig. 4 is a sectiontaken on dotted line :v x, Fig. 3. Figs. 5 and 6 are inl the n'ature ofdiagrams, one showing the furrow and the other representing the pathofthe diamond-cutter.

A indicates the carriage for the rotary cutter. This carriage issupported on a screw,

B, and a guide-rod, C, the former of which passes through ascrew-threadedbearing at one side of the base of the carriage, `and isprovided with a suitable crank or hand wheel, B, by means of which thescrew can be turned in order to propel the carriage, and therebythestone to be dressed. guide-rod are supported so as to be capable ofcause the rotary cutterto traverse the face of The screw and the beingraisedor lowered at either end. For such purpose the said rods can beadjustably connected with supports Xed tothe bed-plate,

or theyl can be supported by vertically-adjust 'able standards D, whichrise from the bedplate E and are adjustably secured thereto by means ofset-screws D or other suitable devices,whereby both the rod and thescrew can be supported in inclined positions, so as to cause the cutterto vary the depth of cut as it is carried along the bottom of thefurrow, as hereinafter described.

The bed-plate E is provided with a longitudinal slot, E, for the passageof the cutter while dressing the stone. This bed-plate is adapted torest upon the stone, as shown in Figs. 2, 3, and 4, and is adjustablyheld thereon by means of a horizontal arm, F, connected at its inner.end with a vertical pivot, G, centered in the eye of the stone, and atits outer end connected with the bed-plate by means of a set-screw, f,which passes through a slot, f,

in the arm and fits in a screw-threaded socket in the bed-plate. Thisarm can be fixed by means of its adjustable connection with thebed-plate, so that when its inner end is iitted upon pivot Gthe machinewill be set more or less to one side of the center of the stone, so asto vary the `line of draft. The pivotal connection of the bed-plate withthe pivot through the medium of the s arm also admits of the machinebeing swung round over the face v of the stone, so as to bring thecutter in position for dressing the several furrows. Thev pivot G isshown tted in a shaft or standard, H, upon which the stone H issupported.

I indicates the rotary cutter-head, which is provided with a blackdiamond or carbon for dressing the stone. I

^ The rotary cutter-shaft K is provided at its upper end with abelt-pulley, L, for a belt, L', which passes around belt-pulleys L2,mounted in an arm, M, which is secured to the carriage.

vIn order to give a vertical adjustment to the carbon.

sleeve which passes through one of a pair of arms on the said carriage,and arranging a spring, n, upon the cutter-shaft between the belt-wheelthereon and the upper end of the sleeve, which is provided with ahand-wheel, N. This sleeve, which is secured -by a setscrew, a', passingthrough a bearing on the carriage through which the sleeve passes, canbe adjusted vertically by loosening said screw and turning the sleeve.The lower end of the sleeve, abutting against the cutter-head, will, ifthe sleeve is lowered, depress the said cutterhead, while if the sleeveis raised the spring will lift the cutter-shaft and cutter to an extentproportionate to the elevation of the sleeve.

The carriage A consists of two parts, a and a', the former of which isprovided with bearings for the sleeve, through which the cuttershaftpasses, while the latter part is supported upon the guide-rod C by meansof a trunnion, O, iitted in the trunnion-box l?, which slides upon saidguide-rod, and on screw B by a box, O', through which said screw passes.By providing this trunnion at one side of the carriage it willaccommodate itself to the positions of the screw or rod when the end ofeither is lowered, thus allowing the carriage to tilt proportionately tothe depression of said rod or screw, so as to admit of a furrow ofvarying width and depth being cut by the diamond or The two parts of thecarriage are connected together by means of a universal joint, formed,for example, by a bolt, Q, passing through said two parts, and servingto maintain a convex projection, q, on one part of the carriage within a.concave seat in the remaining part. The hole through whichthis bolt orpivot passes in part a of the carriage increases in diameter from frontto rear, so as to allow the forward part, ce, of the carriage to betilted to the angle required after the nut upon said bolt has beenloosened.

The operation of my machine is as follows: The furrows are laid off uponthe stone, and then roughed out by means of a millstone-pick or othersuitable tool. The bed-plate is then placed upon the face of the stone,and the arm F adjusted so as to throw the machine suiiiciently to oneside of the center of the stone to cause the cutter, as it is carriedalong the bottom of the furrow,to travel in a true line with the furrowto be dressed, and also so that, after one furrow has been dressed andthe cutter moved out from the verge of the stone,bythen turning theentire machine about its pivot G the cutter can be brought into positionto enter the succeeding furrow, along which it will move in a true linewith said furrow. In order to cause the rotating cutter to conform inits revolutions to the angle `-or transverse inclination of the bottomof the furrow, the entire carriage can be tilted to one side by loweringthe standards supporting screw B, or by lowering the screw or guideindependently of the standards when it is adjustably connectedtherewith; or in place of lowering the screw or guide the forward partof the carriage caranism, i will be both adjusted in horizontal,

planes. To vary the depth, and at the same time maintain the width ofthe furrow, either end of the screw B or the guide-rod can be raisedorlowered by adjusting one of its supporting-standards, or byindependently adjustving the screw or guide, whereby the carriage willbe tilted in a direction diagonally to the line of travel of the cutter.This causes the depth of the furrow to be increased as it approacheseither the verge or the eye of the stone, according to which end of thescrew or guard is the lowest, and by thus causing the angle of thefurrow to vary, a twist will be given to the bottom of the same.To-increase the depth of the furrow at one end and widen the furrow atthe opposite end, it will only be necessary to lower one end of screw Band raise the end of rod C at this end of the machine.

It will of course be understood that where two guides and suitablepropelling mechanism are employed for the carriage said guides will beadjusted in the same way, or substantially the same way, as screw B androd C, as herein shown.

It will be seen that by means of the adjustable guides, and also byreason of the universal joint of the carriage, the cutter can be adaptedto `substantially every conceivable kind of furrow. v The carriage isimpelled by turning the hand-wheel B and the cutter driven by thebelting hereinbefore described. The cutter will be revolved with greatrapidity, so that the stone will be evenly dressed.

Fig. 6 illustrates the motion of the cutter, in which R indicates thecutter and S the line of its travel.

In Fig. 5 the furrow is indicated by T and T, the former indicating theshallow and the latter the deeper portion of the furrow.

In case a slight adjustment of the forward part, a, of the carriageshould be found necessary the nut Q can be slightly loosened and aset-screw7 U, turned on its bearing in part af of the carriage, so as toadjust the forward part of the said carriage.

I have shown the carriage supported on a guide-rod, C, and on apropelling-screw, B, whicn also acts as a guide; but it will be obviousthat the carriage could be supported on two guide-rods or guides capableof being adjusted to various degrees of inclination either by adjustingthe guides on their supports or by adjusting the supports themselves,and in such instance a screw or other analogous motor could be employedsimply for propelling the carriage.

` It will also be seen that the connection between the carriage and thepivot around which it is turned might be varied in construction. As, forexample, arm F might be connected IOO IIO

y. with the bed-plate by an arch having a key, or it could be clampedonto the bed-plate in a variety of ways which will be obvious to anymechanic.

It will be seen that by securing arm lVI or a suitable bracket to thefront part or section, a, of the carriage which carries the rotatingcuttershaft, and by providing said arm with guidepulleys for tle cord orband which transmits motion to the pulley fixed on the cutter-shaft, thebelt or cord is at all times maintained in line with the pulley uponsaid cutter-shaft.

The machine can be readily turned, so 'as to vbring the cutter inposition to successively enter the furrows, and, if desired, the guidescan be adjusted in horizontal planes, and the machine turne'd so as toremove any lumps from the face or lands of the stone. y

By adjusting the carriage or the guides, in the manner hereinbeforedescribed, the cutter can be caused to increase the depth of the furrowtoward either end, or to preserve the same depth throughout its length,and also to vary the width of .the furrow, or to preserve a uniformwidth from end to end of the same.

'What I claim is- 1. In a machine for dressing millstones, thecombination of a slotted base-frame, parallel guide-rods mountedthereon, means, substantially as shown, for raising or lowering saidguide-rods at either end and side of the baseframe, ahorizontally-sliding carriage fitted upon said guide-rods, and averticalrevolving spindle carrying a bottom cutting-tool, mounted in saidreciprocating carriage, substantially as and for the purpose described.e

2. In a millstone-dressing machine, the com,

bination of the carriage consisting of the front bracket or sectionhaving a cone-shaped backand tapering opening, and the rear portion 4ohaving a concave seat and clamping-bolt passing through the same, andthe front section, with the rotary cutter, mounted in said carriage, andthe supporting-frame having devices for adjusting the carriage7substantially 45 as and for the purpose set forth.

3. In a millstone-dressing machine, the coinbination of thevertically-adjustable sleeve N, having screw-threaded lower end andflanged top, and the rotary cutter-spindle K, passing 5o through saidspindle, and having a spring, a, with the adjustable carriage having ascrewthreaded socket for the spindle, and the base or supporting frame,substantially as and for the purpose set forth. .55

4. The carriage for the rotary cutter, conf sisting of two partsconnected together bya universal joint, one of said parts beingsupported onguides adapted to be adjustedin different planes, one ofsaid guides consisting of 60 a feed-screw working in a box on said partof the carriage, and the remaining guide being1 composed of a rod whichpasses through a boX in which a trunnion on the said part ofthe carriageis mounted, whereby the carriage will 65 adjust itself to theinclinations of either guide, substantially as described.

In testimony whereof I have hereunto s et my hand in the presence of twosubscribing wit

